It's late in the day on a weary Friday in August, and sweet, sticky barbecue smoke is drifting over the treetops of a leafy Surrey suburb. Across a tatty croquet lawn, a few bespectacled men in shorts and women in summer skirts are politely shuffling between the sausage queue and a table of beer, sharing anecdotes and holiday tales and discussing the week at work.

They may not look much like media visionaries, but these people help determine what we listen to, what we view and what we read. And they all work here, in Kingswood Warren - the BBC's main research and development centre, nestled among footballers' mansions and parkland. Since the department was established in 1948, the staff of this grand old building have helped develop colour TV, FM and stereo radio, Ceefax, satellite broadcasting, high-definition TV, digital radio and Freeview. They have also had a hand in the production techniques bringing the Beijing Olympics alive for viewers, and the first international broadcast of ultra-high definition TV - which looks set to blow your socks off.

But this is Kingswood Warren's final summer as the home of invention and innovation - after 60 years, the 151 R&D staff will begin leaving in November for a new home in White City, and a third of those will move again with the future media department to Salford. And as the Kingswood era ends, staff members are wondering if this is the beginning of the end of their department, too. There is a palpable sense of gloom: "Someone went to Kingswood Warren, saw a country estate near Gatwick and decided it must be worth a packet," bemoans one.

Academic ethos

Which may leave some saying: so what if they did? Why should the BBC house its staff in stately homes? But that is to ignore the fertile, academic ethos of the place, two hours and a world away from the politics and bureaucracy of White City.

The slightly dilapidated exterior of the building also belies its real power. Kingswood sits on a formidable technical infrastructure - it is one of a handful of buildings in the country with a direct "dark fibre" or large-capacity link to the UK's central internet hub at Telehouse in Docklands. One staff member sneers at the "asset-stripping" decision to sell the building to the residential developer Octagon, instead of a sale to a company such as Google that might appreciate Kingswood's set-up.

So why is the BBC selling up? Is it money? The corporation rejected a previous freedom of information request to disclose the value of the site, but neighbouring properties with a tenth of the land and a fraction of the floorspace sell for up to £4m. "We want R&D to operate closer with our colleagues so we can ... show how technology can help them and spark creative autonomy," says the acting head of broadcast research for BBC Research & Innovation, Andy Bower.

The technical infrastructure will be replicated in White City, where both BBC Property and Siemens - which bought BBC Technology in 2004 - started work this month, and eventually at Salford's MediaCityUK. "The network will be just as large," says Bower. "We're not slimming it down at all - far from it. The broadcast world is changing and will continue to change, so the expectation is that the future media department will grow."

That is if Kingswood staff make the move. Bower acknowledges that relocation (or a long commute) might not appeal to some, many of whom have served 25, 35 or 45 years and are close to retirement. "I hope we don't lose too many," he says. "The key thing is the quality and scope of work that staff can undertake - that's what gets them out of bed every day. Hopefully that will get better."

But morale is low. One staffer says that, while the team had been willing to embrace changes at the start, they have been left demoralised by poor management and continual changes over the details of a move that will see them "squashed into a corner of London W12". Another expresses concern that the weight of staff numbers will drop below a critical mass. They are worried the department will shrink, like the BBC's defunct design department, until it no longer has the resources to tackle significant projects and will then be axed.

Managing decline

The problems started in 2004 with the sale of BBC Technology to Siemens, the departure of the R&D head Peter Bury and a subsequent perceived power battle between Ashley Highfield, the recently departed director of future media and technology, and John Varney, the former chief technology officer, over control of the division. Once Varney had left, staff were unimpressed by the calibre of the executives recruited to oversee R&I for the next four years. Bury's role was split into two jobs, head of broadcast research and head of future media research - but neither has yet been appointed. There is also no overall controller for the whole R&I department."The place desperately needs good leadership or it will fall apart," says one staffer, "and major projects such as digital switchover will be in danger."

"Andy Bower is just managing decline," says another employee, attributing concern over the Kingswood Warren closure to 10% inevitable change and 90% incompetence. "It's soul-destroying for a group of people so dedicated to their work.

"The Siemens deal broke that culture ... it was the demise of doing something because it is for the public good. Siemens do things for the good of Siemens, not for the good of the BBC or the public."

Kingswood today is a strange place; beyond the croquet lawns and grand oak doors are a series of offices, outhouses, laboratories and even an anechoic chamber - an echoless room used for audio experiments. Get locked in there and no one will ever hear you scream.

The loudest voices at the BBC belong to people who work in TV, but there are many more we don't hear - the pioneering engineers, scientists and mathematicians. The rest of the media industry, and the web 2.0 world in particular, are preoccupied with keeping up and spinning the new - but Kingswood is a thing apart, imagining our future 20 years from now.

"This is an unacceptable way to manage a world-class part of the BBC," says one furious member of staff. "There are only two centres in the world recognised as being leaders in the academic and industrial fields of research in broadcasting, and they are NHK in Japan and BBC R&D in Surrey. Soon there will be only one."

Kingswood innovations

HDTV Engineers are working on super-HD in collaboration with Japan's public broadcaster, NHK, experimenting with screens up to 300in wide. The picture quality is produced by using four times as many dots on every line of the image.

3D TV A joint EU project is exploring how to broadcast 3D content. The BBC will focus on content that benefits the most, such as natural history.

Dirac This video compression system makes programmes much easier to record and distribute, which could save the BBC tens of millions of pounds.

Freeview Playback Due to launch in 2009 - with this you can record a whole series with one instruction and, if you want to record two programmes that clash, it will find one of the shows on a repeat broadcast and record it instead.

Audio segmentation A visual "map" of audio programmes that can be used to navigate between sections. In Radio 4's From Our Own Correspondent, for example, the reports appear as darker bands with Kate Adie's links as lighter stripes.

· Watch the interview with Andy Bower at guardian.co.uk/media/video/2008/aug/12/bbc.bbc

• This article was amended on Monday 3 August 2009. We should not have included swingometer election graphics among the Kingswood innovations. This has been corrected.

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